Grinding-wheel.



H. B NICHOLS.

GRINDING WHEEL. APPLICATION FVIL'ED AUG. 22, 1910.

Patented Nov. 29, 1910 unrrn satires are. Enact HENRY B. NICHQLS, OF PHILADELPHIA, PENNSYLVANIA.

, GRINDING-WHEEL.

Specification of Letters Patent.

Original application filed May 27, 1910, Serial No. 563,755. Divided and this application filed August 22,

' 1910. Serial No. 578,367.

To all whom it may concern:

Be it known that I, HENRY B. NIoHoLs, a citizen of the United States, residing at Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented certain new and useful Improvements in Grinding-lVheels, of which the following is a v specification, reference being hadtherein to the accompanying drawing.

My invention relates to grinding machines and especially to certain forms of grinding wheels intended to be used with automatic calipering devices Briefly stated the invention comprises a wheel having a clamping plate in which are set ring inserts of anti-friction material, upon which the feeler or contact device of an automatic caliper is adapted to rest during the operation of the wheel, so as to indicate wear on the same, by recession of the clamping plate, and to compensate for the same as disclosed imm applications. and patents as follows: Serial No. 535,091, filed December 27,1009, as a division of each of two prior applications, Serial No". 457,875, filed September 5, 1908, patented December 28, 1909, Patent No. 944,902.; and Serial No.

472,236, filed January 14,1909, patented De-.

cember 28, 1909, Patent No. 944,903. In the twopatented cases the claims are directed to grinding machines .as such; in the prior application No. 535,091, I have claimed the automatic calipers as such; in a vdivisional application Serial No. 563,755, filed May 27, 1910, I have claimed a grinding wheel with anti-friction rings or inserts in its face or back, which broadly speaking might be either in the body of the wheel or in the metal clamps thereof; and in the present case, which is a division of'my said prior application Serial No. 503,755, I claim specifically a wheel with an anti-friction insert, in the form of a ring'or rings, applied to the clamping plate or plates.

My inventionis shown in the accompanying drawing in which- Figure 1 is a transverse section of a grimlsecondary clamping plate 72. In the face of the clamp it are the inserts F I constituting the subject of the present invention. These inserts may be formed of any one of several kinds of material but the best material I have found as a body ingredient is graphite. After the plate in is grooved, the anti-friction rings are molded in the grooves. One process of molding'consists of mixing graphite with water to form a thick paste, and then pressing this into the grooves so as to expel as much of the water as possible, and subsequently evaporating the rest. This process, however, is not cntirclyreliahle in its results because of the shrinkage of the paste'in drying, unless constant and very heavy pressure is employed, such'as that ohtainable by I hydraulic. means. Another method employed is-a binder which under ordinary conditions of pressure and temperature is a solid, and which can remain permanently incorporated with the graphite. Such a binder l have found in sulfur, which does not impair the efficiency of the graphite for my purpose. It is first melted and the powdered graphite is stirred or ground into it in the proportion of two parts of graphite to one of sulfur. The grooved flange is then heated to a temperature of about 212 Fahrenheit, the paste is pressed into the grooves, and the whole is covered and allowed to cool uniformly. In whichever way they are formed, the two rings F and F present anti-friction surfaces for the calipers, sufiiciently hard for accurate CllmQIISIOIIHl By using a metal clamping plate with the ring inserts set into it, 1 gain several advantages. vFor one thing, it enables me to use standard or stock wheels; for anothcr,,.itenables pure graphitev to be employed, if inserted in the grpoves under pressure, which of course would be impossiblc when applying the material to the body of a grinding wheel direct.

I have shown the grooves in the flange 12, as dove-tail or under-cut grooves, but it is to be wider-stood that this is subject to variation, and other shapes may be employed without departing from the invention. Other changes may obviously be made in non-essentials such as the shape, dimensions and arrangements of the clamping plate and hub and the like. It is to be understood that all of these are contemplated by me, when necessary, the essential feature being the PatenteIINiiv. 29, 1910.

ring insert of inserts in a' clamping plate, for the purpose stated.

, I' have deemed it unnecessary to show the calipers herein, since the same are fully disclosed in all of my prior applications ami patents referred to which are to be real with this application, in order to fully understand t 1e invention.

Havingthus described my invention What I claim and desire to secure by Letters Pat'- ent is- I A grinding Wheel having its body of abrasive material, a clamping plate adapted to secure said body to a hub or shaft, said plate having an annular groove in its surface, and 15- HENRY B. NICHOLS.

lVitnesses C. B. VOYNOW, C. H. RYAN. 

